versions: Adjust checksum column to be NOT NULL

migrations/2022-08-28-191319_non-null-checksum/down.sql

@@ -0,0 +1,2 @@
+alter table versions
+    alter column checksum drop not null;

migrations/2022-08-28-191319_non-null-checksum/up.sql

@@ -0,0 +1,2 @@
+alter table versions
+    alter column checksum set not null;

src/models/version.rs

@@ -23,7 +23,7 @@ pub struct Version {
     pub license: Option<String>,
     pub crate_size: Option<i32>,
     pub published_by: Option<i32>,
-    pub checksum: Option<String>,
+    pub checksum: String,
     pub links: Option<String>,
 }
 

src/schema.rs

@@ -990,10 +990,10 @@ table! {
         published_by -> Nullable<Int4>,
         /// The `checksum` column of the `versions` table.
         ///
-        /// Its SQL type is `Nullable<Bpchar>`.
+        /// Its SQL type is `Bpchar`.
         ///
         /// (Automatically generated by Diesel.)
-        checksum -> Nullable<Bpchar>,
+        checksum -> Bpchar,
         /// The `links` column of the `versions` table.
         ///
         /// Its SQL type is `Nullable<Varchar>`.